Isatin derivatives bearing a fluorine atom. Part 1: Synthesis, hemotoxicity and antimicrobial activity evaluation of fluoro-benzylated water-soluble pyridinium isatin-3-acylhydrazones

Anticancer and Antiphytopathogenic Activity of Fluorinated Isatins and Their Water-Soluble Hydrazone Derivatives

A series of new fluorinated 1-benzylisatins was synthesized in high yields via a simple one-pot procedure in order to explore the possible effect of ortho-fluoro (3a), chloro (3b), or bis-fluoro (3d) substitution on the biological activity of this pharmacophore. Furthermore, the new isatins could be converted into water-soluble isatin-3-hydrazones using their acid-catalyzed reaction with Girard's reagent P and its dimethyl analog. The cytotoxic action of these substances is associated with the induction of apoptosis caused by mitochondrial membrane dissipation and stimulated reactive oxygen species production in tumor cells. In addition, compounds 3a and 3b exhibit platelet antiaggregation activity at the level of acetylsalicylic acid, and the whole series of fluorine-containing isatins does not adversely affect the hemostasis system as a whole. Among the new water-soluble pyridinium isatin-3-acylhydrazones, compounds 7c and 5c,e exhibit the highest antagonistic effect against phytopathogens of bacterial and fungal origin and can be considered useful leads for combating plant diseases.

Synthesis and Antimicrobial, Antiplatelet, and Anticoagulant Activities of New Isatin Deivatives Containing a Hetero-Fused Imidazole Fragment

A series of isatin derivatives containing an adenine or theophylline fragment have been synthesized. The corresponding N′-[2-(trimethylammonio)acetyl] and N′-(2-pyridinioacetyl) hydrazones have been found to exhibit neither cytotoxicity nor hemotoxicity. Quaternary salts based on adenine derivatives of 5-methyl- and 5-ethylisatins showed the highest antiplatelet activity which exceeded the activity of acetylsalicylic acid by a factor of 1.5.

Isatin-3-acylhydrazones with enhanced lipophilicity: synthesis, antimicrobial activity evaluation and the influence on hemostasis system

Water-soluble trialkylammonium isatin-3-hydrazone derivatives bearing hydroxybenzyl substituent were easily synthesized with high yields. XRD studies confirmed the presence of these compounds as trans-( Z )-isomers in a crystal. It was shown that an increase in the lipophilicity of the cationic center leads to an increase in activity against Gram-positive bacteria Staphylococcus aureus and Bacillus cereus, including methicillin-resistant (MRSA) strains. The MIC values of the leading compounds turned out to be 2-100 times higher than the MIC of norfloxacin against the MRSA strains in the absence of hemo- and cytotoxicity. Antiaggregation and anticoagulation properties were in vitro better than for acetylsalicylic acid and sodium heparin drugs. It has been shown by UV spectroscopy and fluorescence microscopy that the mechanism of antimicrobial action of new acylhydrazones is associated with their ability to destroy the bacterial cell membrane.

Ammonium-Charged Sterically Hindered Phenols with Antioxidant and Selective Anti-Gram-Positive Bacterial Activity

The increase in the resistance of pathogens, in particular Staphylococcus aureus, to the action of antibiotics necessitates the search for new readily available and non-toxic drugs. In solving this problem, phenolic acylhydrazones have high potential. In this communication, the synthesis of quaternary ammonium compounds containing a differently substituted phenolic moiety has been performed. An initial study of antimicrobial activity showed that these compounds are highly selective against S. aureus and B. cereus. The highest activity (MIC 2.0 μm) was shown by hydrazones containing a catechol fragment. These compounds are more than 3-fold more active against S. aureus and 3-10-fold more active against B. cereus than norfloxacin. Low hemolytic and high antioxidant activities of all new compounds were also established.